The wooden shipping pallet has been used for handling and transporting materials for many years and there are millions of such pallets in widespread use today. Wooden pallets are the platform on which virtually all of the world's goods have been stored, warehoused, transported, and distributed. As such, they are an integral and very important component of worldwide commerce.
One of the problems associated with wooden pallets, especially when they are used to carry food products, is poor sanitation. Pallets are generally stored outdoors, or in warehouses where they are exposed to the accumulation of dirt, debris, and the infiltration of a wide variety of parasites. Mold and bacteria also grow on wooden pallet surfaces. Constant cleaning and/or fumigation is required to maintain adequate health standards when food products are carried by the pallets. Wooden pallets are difficult to sanitize because of the inherent cracks, voids, and imperfections in the wood surface where dirt and micro-organisms readily accumulate. In particular, raw fish and meat are easily contaminated by simple contact with a pallet. Additionally, the porous surface of wood pallets makes them particularly difficult, if not impossible, to sanitize. Splinters and wood chips picked up by the food products being transported or stored also pose a significant health threat.
Attempts to address the problems of sanitation have led to a wide variety of wooden pallet substitutes. These include pallets made of plastic, steel, aluminum, fiber board, and combinations of these materials. One sanitary solution to the problem is the pallet totally fabricated from plastic. This totally plastic pallet surface is impervious to dirt and micro-organisms and is thus easily cleaned and sanitized. While the plastic pallet provides a sanitary surface, it is not, however, very cost effective, because plastic pallets can cost up to ten times as much as their wooden counterparts. Also, there are many millions of wooden pallets in use today. Conversion to use of all-plastic pallets would render the wooden pallets obsolete resulting in significant lost investment and countless tons of solid waste.
Description of typical prior art approaches to the problem of providing sanitary pallets may be found in a number of U.S. patents.
U.S. Pat. No. 3,273,518 to Shina, issued in 1966, discloses a thin, rectangular pallet, including four leg portions, made of corrugated paperboard that is coated with a thin transparent layer of polyethylene to render it substantially waterproof. Of interest is a showing of a series of openings or holes in the rectangular flat top sheet that permit air or liquids to pass through it.
U.S. Pat. No. 5,473,995 to Gottlieb discloses a pallet top also made of corrugated hardboard which is described as being more hygienic than the conventional wooden pallet top. The background section provides a good description of the problem being addressed, namely the unsanitary propensities of wooden pallets, especially in the food handling industries.
U.S. Pat. No. 5,778,801 to Delacour provides a more recent (1998) teaching of a pallet made of solid plastic materials such as polyethylene or polypropylene for hygienic reasons. The pallet structure, however, includes the conventional top platform and block type legs for conventionally being lifted by a forklift.
Additional prior art teachings of background interest are found in U.S. Design Pat. No. 364,030 to Pigott, et al., which discloses the ornamental design for what appears to be a completely plastic pallet including arrays of apertures, and U.S. Pat. No. 4,871,063 to Kumbier. Which discloses a multiple layer pallet cover for protecting the upper surfaces of a load resting on a pallet.
While each of these prior art approaches acknowledges the importance of a high degree of sanitation consciousness when transporting raw foodstuffs, they address the task with ever-increasing apparatus complexity, and basic cost effectiveness has been clearly sacrificed. It is this cost-effective need that the present invention admirably meets with its elegant and straightforward retrofittable plastic pallet cover approach.